There's an additional issue with Collpased Ceiling: the card says that, when undefeated, any character at that location must encounter it on their *first* exploration.
However, if a character explores a second time during his turn (for example after failing the check to defeat collapsed ceiling and playing a blessing or ally to continue), he should encounter the first facedown card on the location deck. In PA, the game will force you to encounter the barrier over and over, which is not right.